Date:
20130529
Docket:
T-1044-11
Citation:
2013 FC 573
Ottawa, Ontario,
May 29, 2013
PRESENT: The
Honourable Mr. Justice O'Reilly
BETWEEN:
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BAYER INC AND BAYER PHARMA
AKTIENGESELLSCHAFT
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Applicants
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and
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COBALT PHARMACEUTICALS COMPANY
COBALT PHARMACEUTICALS INC AND THE MINISTER OF HEALTH
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Respondents
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REASONS FOR
JUDGMENT AND JUDGMENT
I.
Overview
[1]
The
applicants, Bayer, seek an order prohibiting the Minister of Health from
issuing a Notice of Compliance [NOC] to the respondents, Cobalt, in respect of
a generic version of Bayer’s product, an oral contraceptive marketed as
YASMIN®. The NOC would permit Cobalt to market tablets containing drospirenone,
a compound claimed in Bayer’s Canadian Patent No 2,261,137 [the ‘137 patent],
which does not expire until August 11, 2017. Bayer contends that Cobalt’s
product would infringe the ‘137 patent, while Cobalt alleges that it would not.
In addition, Cobalt alleges that the ‘137 patent is invalid for obviousness.
[2]
I
am satisfied, based on my reading of the ‘137 patent, that Cobalt’s allegation
that its product would not infringe the ‘137 patent is justified. Therefore, I
must dismiss Bayer’s application. It is unnecessary to consider the issue of
whether the patent is invalid.
[3]
The
issues are:
1. What
is the proper construction of the ‘137 patent?
2. Are
Cobalt’s allegations of non-infringement justified?
II. The ‘137 Patent
[4]
The
‘137 patent is entitled “Process for Producing Drospirenone”. It states that
the invention relates to a process for producing drospirenone, as well as two
intermediate compounds referred to as ZK 92836 and ZK 90965. The patent
describes the process for producing drospirenone in the prior art and
characterizes the invention as being a “new production process for drospirenone,
which is more selective and simpler in execution than that from the prior art
and, in addition, is ecological (savings of a chromium trioxide oxidation).”
[5]
The
patent then sets out the new process showing three steps: (1) hydrogenation to
make ZK 92836; (2) oxidation through the use of ruthenium salts (such as RuCl3,
RuO2, KRuO4, K2RuO4, but
“preferably” a catalytic amount of RuCl3) to make ZK 90965; and then
(3) dehydration to make drospirenone. The patent describes the second step,
oxidation, as “a key reaction”. The patent includes an example of the
three-stage process in which a catalytic amount of the ruthenium salt RuCl3
is used at the oxidation stage.
[6]
Claim
1 of the patent addresses the three-step process (using ruthenium salt at the
oxidation stage) for producing drospirenone. Claims 2 to 11 address variations
on the process, although none suggests any alternative to the use of a
ruthenium salt at the oxidation stage. Indeed, Claim 5 specifically mentions the
four ruthenium salts referred to in the patent’s disclosure (RuCl3,
RuO2, KRuO4, K2RuO4), while Claims
6 and 11 cover the preferred oxidizing agent, a catalytic amount of the
ruthenium salt RuCl3.
[7]
Claim
12 claims all of the processes in Claims 1 to 11 which yield two named
contaminants in a concentration of less than 0.2%.
[8]
Claim
13 is the only claim in issue here. It claims a product “prepared according to
the process of claim 12, wherein the product comprises drospirenone and less
than 0.2%” of the two contaminants identified in Claim 12.
[9]
The
remaining claims address the intermediate ZK 90965 (Claim 14), and processes
for making it (Claims 15 and 16).
III.
Issue
One – What is the proper construction of the ‘137 patent?
[10]
As
mentioned, the only claim in issue is Claim 13, which addresses a “product
prepared according to the process of Claim 12”. Bayer maintains that Claim 13
is a pure product claim. It contends that the claim should be read as if the
words “prepared according to the process of Claim 12” were not there.
[11]
Bayer
presents two reasons for its construction of Claim 13. First, it says that its
construction is required as a matter of law according to Hoffman-LaRoche
& Co v Commissioner of Patents, [1955] S.C.R. 414. Second, Bayer submits
that its construction conforms with the interpretation that a skilled person
would give to Claim 13.
[12]
I
am not persuaded that Bayer’s construction is correct in law or consistent with
how a skilled person would read Claim 13. In my view, Claim 13 incorporates the
patented process for making drospirenone.
[13]
In
the alternative, Bayer argues that the process referred to in Claim 13 does not
require the presence of a ruthenium salt at the oxidation stage; any
appropriate metal salt could be substituted at the oxidation stage and still
fall within the claims of the patent.
[14]
Again,
based on my reading of the ‘137 patent, I cannot accept Bayer’s construction.
In my view, the presence of a ruthenium salt at the oxidation stage is an
essential element of the invention described in the ‘137 patent.
(1) Bayer’s
construction of Claim 13 is not required by law
[15]
Bayer
relies on Hoffman-LaRoche, above, for the following propositions: (i)
product-by-process claims should be read as hypothetical claims for the product
alone. If the product is not new, then the claims are invalid, even if the
process is new. Therefore, any reference to a process within a claim for a
product made according to that process should be disregarded; (ii) claims must
be given the same construction for all purposes, including invalidity and
infringement. Since Hoffman-LaRoche requires product-by-process claims
to be read as claims for the product alone for the purposes of an invalidity
challenge, I must also consider Cobalt’s allegations of non-infringement as
against Claim 13 as if that claim were for the product alone. According to that
construction, Cobalt’s allegation of non-infringement would not be justified
because Cobalt’s product is essentially the same as Bayer’s.
[16]
I
disagree with Bayer’s legal arguments. In particular, I do not read in Hoffman-LaRoche
a requirement to construe product-by-process claims in the manner Bayer
puts forward. In my view, product-by-process claims should not always be read
without reference to the specified process. Therefore, Bayer’s Claim 13 must be
construed as including the patented process.
[17]
When
Bayer obtained the ‘137 patent in 1996, drospirenone was a known, and already
patented, compound. As described above, the ‘137 patent is directed at an
improved process for making drospirenone and the allegedly purer form described
in Claim 13.
[18]
Hoffman-LaRoche
tells us that a new patent cannot be obtained for a known compound even if a
new process has been discovered for making it. Accordingly, claims for a
product made by a particular process should be assessed as if they were claims
for the product alone and should be upheld only if the product is new. In other
words, a new process for making an old compound does not justify a new patent
for that same compound.
[19]
Assuming
that the compound in Claim 13 is new (ie, a form of drospirenone with a
particular purity), an issue I need not decide here, the issue in Hoffman-LaRoche
simply does not arise.
[20]
In
that case, Hoffman-LaRoche had invented a new process for manufacturing
aldehyde, a known substance. It sought a patent for the product made according
to that process. The Supreme Court of Canada held that Hoffman-LaRoche could
not obtain a new patent for the old compound, even though a new process for
making it had been invented. In that sense, the patent’s claims had to be read
as if they were claims for the compound alone, and only if the compound was new
could the claims be valid.
[21]
Accordingly,
in considering whether Bayer would be entitled to a patent for the drospirenone
product made by its new process, I would have to consider whether that product,
regardless of how it was made, was new. That is an issue of invalidity, not
claims construction. Hoffman-LaRoche does not establish a rule of claims
construction requiring that all product-by-process claims be read as if there
were no reference to the process within the claims. It merely provides that
claims for a product (even a product made by a new process) must meet the
definition of an invention.
[22]
Therefore,
as a matter of law, I cannot accept Bayer’s assertion that Claim 13 should be
construed as if the words “[a] product prepared according to the process of
claim 12” did not exist.
(2) A
skilled person would not construe Claim 13 as a product claim
[23]
The
parties agree that a skilled person for present purposes would be a chemist with
1 to 5 years of experience.
[24]
Bayer
argues that a skilled person would read Claim 13 as a claim for the purer form
of drospirenone, regardless of how it was made. Bayer’s expert, Dr Mark Lautens
(Professor of Organic Chemistry, University of Toronto) read Claim 13 that way.
Indeed, according to Bayer, a skilled person would not read Claim 13 as
including the patented process because that would render redundant the other
claims in the patent specifically addressing that process.
[25]
Dr
Lautens’ view is that the ‘137 patent discloses the highly pure form of
drospirenone, as well as the form of drospirenone prepared according to the
process set out in the patent (avoiding toxic chromium), and the simplified
process for making drospirenone. His opinion is that Claim 13 claims the
product alone.
[26]
In
contrast, Cobalt’s expert, Dr Lakshmi Kotra (Professor, Faculty of Pharmacy,
University of Toronto), read Claim 13 as covering drospirenone, prepared
according to the process in Claim 12, and having the specified purity profile.
[27]
I
cannot accept Dr Lautens’ construction of Claim 13. Claim 13 clearly makes
reference to certain impurities but nothing in the disclosure suggests that
this purity profile was an object of the invention. Nor is there any evidence
that the previously known drospirenone product was impure. Most importantly,
Claim 13 clearly and expressly incorporates the process described in Claim 12.
[28]
Nor
do I accept that construing Claim 13 as including the patented process would
render the other claims to that process redundant. Those other claims,
described above, stand on their own. The fact that Claim 13 incorporates Claim
12 (and, in turn, Claims 1 to 11) does not render those other claims
superfluous. Claim 13 addresses a product made by a specified process. The
process itself is patentable and can, as the ‘137 patent does, be claimed
independently.
[29]
In
short, Claim 13 relates to a drospirenone product made according to the
three-step process described in the patent and claimed in Claim 12, with a
particular level of purity.
(3) The
presence of a ruthenium salt is an essential element
[30]
Bayer
contends that if Claim 13 is construed as containing the process of Claim 12,
then the process of Claim 12 should not be read as including oxidation in the
presence of a ruthenium salt as an essential element. The patent, Bayer says,
only requires oxidation in the presence of an appropriate metal salt, not
necessarily ruthenium.
[31]
I
cannot agree with Bayer’s interpretation of the ‘137 patent.
[32]
The
patent describes a three-step process for making drospirenone. The first step,
hydrogenation, and the third step, dehydration, are both routine and
well-understood operations that are relatively insignificant aspects of the
inventive process. The “key reaction” of the invention is the second step,
oxidation in the absence of chromium trioxide. This step achieves the
ecological objective of the patent by avoiding the prior art’s use of toxic
chromium.
[33]
The
only metal salts mentioned in the patent as being suitable alternatives to
chromium are ruthenium salts. As mentioned, ruthenium salts are specifically
included in Claims 1, 5, 6 and 11. No alternatives are cited, and there is no
reference to the possibility that other metal salts might work. The patent’s
disclosure also contains numerous references to ruthenium. There is only one
passage that could be read as admitting of an alternative to ruthenium:
Another very basic advantage of
the process according to the invention compared to the prior art lies in the
range of ecology. It has been possible to replace the previously used toxic
chromium compounds, which so far have been used in the form of pyridinium
dichromate salts for oxidation and must subsequently be disposed of in the form
of their solutions, by catalytic amounts of a metal.
[34]
This
general statement, in the context of the patent as a whole, cannot expand the
breadth of the patent’s invention. The invention is set out unambiguously in
the claims and the only compounds mentioned as being suitable candidates for
the key reaction of the invention are ruthenium salts. The clear language of
the claims limits the scope of the invention (Free World Trust v Électro
Santé Inc., 2000 SCC 66, at para 51). Here, the invention is a process for
making drospirenone that uses ruthenium salts as an alternative oxidizing agent
to chromium trioxide.
[35]
I
note that Dr Lautens’ opinion is that ruthenium salts are simply mentioned as
examples for appropriate metal salts. He maintains that a skilled reader would
have realized that other metal salts would work.
[36]
However,
Dr Lautens does not mention any potential alternatives to ruthenium that would
be appropriate, nor does he make reference to the patent’s claims where only
ruthenium salts are identified as oxidizing agents.
IV.
Issue
Two – Are Cobalt’s allegations of non-infringement justified?
(1) Burden of Proof
[37]
It is well-accepted that, once a second person has
presented sufficient evidence to give the allegations in its NOA an air of
reality, the burden falls on the first person to show on a balance of probabilities
that the second person’s allegations are unjustified (Pfizer Canada Inc v
Apotex Inc, 2007 FC 26, at paras 9-12). (A recent decision of this Court
seems to suggest that the burden of proof falls on the second person, but that
appears to be the result of a typographical error: see Pfizer Canada Inc v
Pharmascience Inc, 2013 FC 120, at para 27). In this case, in keeping with
the prevailing case law, the parties agree that the burden falls on Bayer to
show that Cobalt’s allegations of non-infringement are unjustified.
(2) Cobalt’s allegation of non-infringement is justified
[38]
Cobalt’s
Notice of Allegation [NOA] contended that its product would not infringe Claim
13 because it would not use the process for making drospirenone that is
described in the ‘137 patent. In particular, Cobalt’s process would not yield
the intermediate compounds that form part of the invention set out in the ‘137
patent. Further, Cobalt would not use the three-step process identified in
Claim 1 of the patent and, in particular, would not employ a ruthenium salt as
an oxidizing agent. For present purposes, I need not describe Cobalt’s process
in any further detail.
[39]
As
discussed above, Bayer contends that the process described and claimed in the
‘137 patent includes some inessential elements and, therefore, even though
Cobalt would use a different process to produce drospirenone, its claim of
non-infringement is not justified. Cobalt’s process would still come within the
scope of the process claims of the ‘137 patent, even though its process differs
from Bayer’s in certain respects.
[40]
However,
in light of my conclusion that Claim 13 incorporates the process for making
drospirenone set out in the ‘137 patent, which includes the key oxidation
reaction with a ruthenium salt, I cannot agree with Bayer’s submission. In
short, Cobalt relies on a non-infringing process to make drospirenone.
Accordingly, Bayer has failed to show that Cobalt’s allegation of
non-infringement is unjustified.
V.
Conclusion
and Disposition
[41]
Bayer’s
burden was to show that Cobalt’s allegation of non-infringement was
unjustified. Claim 13 of the ‘137 patent addresses a product made by the
three-step process set out in the patent, an essential element of which is
oxidation in the presence of a ruthenium salt. As this essential operation is
not part of Cobalt’s process, I find that Bayer has failed to discharge its
burden. I must, therefore, dismiss Bayer’s application for an order prohibiting
the Minister of Health from issuing a NOC to Cobalt, with costs.
JUDGMENT
THIS
COURT’S JUDGMENT is that:
1. The
application for an order prohibiting the Minister of Health from issuing a
Notice of Compliance to the respondents is dismissed, with costs.
“James W. O’Reilly”
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